Block copolymer

ABSTRACT

The present application provides the block copolymers and their application. The present application may provide the block copolymers that have excellent self assembling and phase separation properties and therefore that can be effectively used in various applications. The present application may also provide applications of the block copolymers.

TECHNICAL FIELD

The present application relates to block copolymers and theirapplication.

BACKGROUND

Block copolymers have molecular structures in which polymer subunitshaving chemically different structures from each other are linked bycovalent bonds. Block copolymers are capable of forming periodicallyaligned structure such as the sphere, the cylinder or the lamellathrough phase separations. Sizes of domains of the structures formed bythe self assemblies of block copolymers may be adjusted in a wide range,and various shapes of structures can be prepared. Therefore, they can beutilized in pattern-forming methods by lithography, various magneticrecording mediae or next generation nano devices such as metal dots,quantum dots or nano lines, high density magnetic storage mediae, andthe like.

DESCRIPTION Technical Object

The present application provides a block copolymer, a polymer layerincluding the block copolymer, a method for forming the polymer layerand a pattern-forming method.

Technical Solution

The block copolymer may include a first block and a second block that isdifferent from the first block. The first or second block may include aside chain as described below. Hereinafter, in a case where one blockamong the first and second blocks includes the side chain, the blockincluding the side chain may be referred to as a first block. The blockcopolymer may be a diblock copolymer that includes only the above firstand second blocks or may be a block copolymer that includes anadditional block other than the first and second blocks.

The block copolymers may be phase-separated, since they comprise the twoor more polymeric chains linked to each other via covalent bonds. In thepresent application, since the block copolymer satisfies at least oneparameter as described below, the phase-separation can be veryeffectively occurred, and therefore it can form a nano-scaled structureby a microphase separation. According to the present application, bycontrolling sizes such as molecular weights or relative ratios betweenblocks, Sizes or shapes of the nano structure can be freely adjusted. Bythe above, the block copolymer can freely form various sizes ofphase-separated structure such as the sphere, the cylinder, the gyroid,the lamella and the reversed structure and the like. The presentinventors have found that, if block copolymers satisfy at least oneparameter among ones described below, the self assembling properties andthe phase separation properties as described above are largely improved.It is confirmed that it is possible to make the block copolymer to showa vertically aligning property by making the block copolymer to satisfyan appropriate parameter. The term “vertically aligning property” asused herein may refer to aligning property of the block copolymer andmay refer to a case where the nano scaled structure formed by the blockcopolymer is aligned vertically to a direction of a substrate.Techniques controlling an aligning of a self assembled structure of ablock copolymer to be vertical or parallel with respect to varioussubstrates are a big part of practical application of a block copolymer.Conventionally, the aligning direction of the nano scaled structure in alayer of a block copolymer depends on what block among blocks formingthe block copolymer is exposed to a surface or an air. Generally, sincelots of substrates are polar and the air is non-polar, a block havingmore polarity than the other block in the block copolymer wets on thesubstrate and a block having less polarity than the other block in theblock copolymer wets with respect to the interface between the air. Manytechniques are proposed in order for blocks of a block copolymer havingproperties different from each other to wet simultaneously toward thesubstrate, and a most typical method is to control the aligning bypreparing the neutral surface. However, in one embodiment, bycontrolling the parameters below, the block copolymer may be verticallyaligned with respect to substrates, to which conventionally knowntreatment for accomplishing the vertical alignment including the neutralsurface treatment is not performed. For example, block copolymersaccording to one embodiment of the present application can show thevertical aligning property on both of hydrophobic surfaces andhydrophilic surfaces, to which any pre-treatment is not performed.Further, in an additional embodiment, the vertical alignment may beaccomplished with respect to a large area in a short time by a thermalannealing.

In one embodiment, an absolute value of a difference between surfaceenergies of the first and the second blocks may be 10 mN/m or less, 9mN/m or less, 8 mN/m or less, 7.5 mN/m or less or 7 mN/m or less. Theabsolute value of the difference between surface energies may be 1.5mN/m or more, 2 mN/m or more or 2.5 mN/m or more. The structure in whichthe first and the second blocks, the absolute value of the differencebetween the surface energies of which is within the above range, arelinked via the covalent bond may realize an effective microphaseseparation by a phase separation due to appropriate un-compatibilities.In the above, the first block may be the block having the chain asdescribed above or a block comprising an aromatic structure that doesnot have a halogen atom as described below.

The surface energy may be measured by using a drop shape analyzer(DSA100 product manufactured in KRUSS, Co.). Specifically, the surfaceenergy may be measured with respect to a layer prepared by coating acoating solution prepared by diluting a sample (a block copolymer or ahomopolymer) to be measured in fluorobenzene to a solid content of about2 weight % on a substrate so as for the coated layer to have a thicknessof 50 nm and a coated area of 4 cm² (a width: 2 cm, a length: 2 cm);drying the coated layer for about an hour at the room temperature; andthen performing a thermal annealing for about an hour at 160° C. On thelayer after the thermal annealing is performed, deionized water of whichthe surface tension is known is dropped and then the contact angle ismeasured. The above process for obtaining the contact angle of thedeionized water is repeated 5 times, and the average value of the 5obtained contact angles are calculated. Identically, on the layer afterthe thermal annealing is performed, diiodomethane of which the surfacetension is known is dropped and then the contact angle is measured. Theabove process for obtaining the contact angle of the diiodomethane isrepeated 5 times, and the average value of the 5 obtained contact anglesare calculated. After that, the surface energy may be obtained bysubstituting a value (Strom value) regarding the surface tension of thesolvent through the Owens-Wendt-Rabel-Kaelble method using the obtainedaverage values of the contact angles of the deionized water and thediiodomethane. The surface energy of each block in the block copolymermay be obtained by using the above described method with respect to ahomopolymer prepared by monomers forming the corresponding block.

In a case where the block copolymer comprises the above described chain,the block comprising the chain may have a larger surface energy than theother block. For example, if the first block comprises the chain, thefirst block may have a larger surface energy than the second block. Inthis case, the surface energy of the first block may be in a range fromabout 20 mN/m to about 40 mN/m. In another embodiment, the surfaceenergy of the first block may be about 22 mN/m or more, about 24 mN/m ormore, about 26 mN/m or more or about 28 mN/m or more. The surface energyof the first block may be about 38 mN/m or less, about 36 mN/m or less,about 34 mN/m or less or about 32 mN/m or less. Such a block copolymerincluding the above first block and showing the above difference betweensurface energies of blocks may show an excellent self assemblingproperty.

The parameter may be accomplished by, for example, controlling the blockcopolymer.

In one embodiment, the block copolymer satisfying the above parametermay include a side chain having chain-forming atoms in the first orsecond block. Hereinafter, for the sake of convenient explanation, theblock comprising the side chain may be referred to as the first block.

The term “chain-forming atoms” as used herein refers to atoms formingthe side chain linked to the block copolymer and atoms forming a linearstructure of the side chain. The side chain may have a linear orbranched structure; however the number of the chain-forming atoms iscalculated only by the number of atoms forming the longest linear chain.Therefore, other atoms such as, in a case where the chain-forming atomis the carbon atom, the hydrogen atom that is linked to the carbon atomand the like are not calculated as the number of the chain-formingatoms. Further, in a case of the branched chain, the number of thechain-forming atoms is the number of atoms forming the longest chain.For example, the chain is n-pentyl, all of the chain-forming atoms arecarbon atoms and the number thereof is 5. If the chain is2-methylpentyl, all of the chain-forming atoms are also carbon atoms andthe number thereof is 5. The chain-forming atoms may be the carbon, theoxygen, the sulfur or the nitrogen, and the like and appropriatechain-forming atoms may be the carbon, the oxygen or the nitrogen; orthe carbon or the oxygen. The number of the chain-forming atoms may be 8or more, 9 or more, 10 or more, 11 or more; or 12 or more. The number ofthe chain-forming atoms may be 30 or less, 25 or less, 20 or less or 16or less.

In another embodiment, one or both of the first block and the secondblock may include at least aromatic structure in the block copolymersatisfying the above parameter. Both of the first block and the secondblock may include the aromatic structure(s) and, in this case, thearomatic structure in the first block may be the same as or differentfrom the aromatic structure in the second block. Further, at least oneblock among the first and second blocks of the block copolymersatisfying parameters described in this document may include the sidechain or at least one halogen atom as described below, and such a sidechain or at least one halogen atom may be substituted with the aromaticstructure. The block copolymer may include two or more blocks.

As described, the first block and/or the second block of the blockcopolymer may include the aromatic structure(s). Such an aromaticstructure may be included in one of or both of the first block and thesecond block. In a case where both of the blocks include the aromaticstructures, the aromatic structure in the first block may be the same asor different from the aromatic structure in the second block.

The term “aromatic structure” as used herein may refer to an aryl orarylene group, and may refer to a monovalent or a bivalent substituentderived from a compound including one benzene ring structure or astructure, in which at least two benzene rings are linked with sharingone or two carbon atoms or by an optional linker, or a derivative of thecompound. The aryl or arylene group may be, unless defined otherwise, anaryl group having 6 to 30, 6 to 25, 6 to 21, 6 to 18, or 6 to 13 carbonatoms. As the aryl or arylene group, a monovalent or a bivalentsubstituent derived from benzene, naphthalene, azobenzene, anthracene,phenanthrene, tetracene, pyrene, benzopyrene, and the like may beillustrated.

The aromatic structure may be a structure included in a main chain ofthe block or may be a structure linked to the main chain of the block asa side chain. For example, appropriate adjustment of the aromaticstructure that may be included in each block may realize controlling ofthe parameters.

For example, in order to control the parameter, the chain having 8 ormore chain-forming atoms may be linked, as a side chain, to first blockof the block copolymer. In this document, the term “side chain” and theterm “chain” may indicate to the same object. In a case where the firstblock includes the aromatic structure, the chain may be linked to thearomatic structure.

The side chain may be a chain linked to a main chain of polymer. Asdescribed, the side chain may be a chain including 8 or more, 9 or more,10 or more, 11 or more or 12 or more chain-forming atoms. The number ofthe chain-forming atoms may be 30 or less, 25 or less, 20 or less or 16or less. The chain-forming atom may be carbon, oxygen, nitrogen orsulfur, or appropriately carbon or oxygen.

The side chain may be a hydrocarbon chain such as an alkyl group, analkenyl group or an alkynyl group. At least one carbon atom in thehydrocarbon chain may be replaced with the sulfur atom, the oxygen atomor the nitrogen atom.

In a case where the side chain is linked to the aromatic structure, thechain may be directly linked to the aromatic structure or may be linkedto the aromatic structure via a linker. The linker may be an oxygenatom, a sulfur atom, —NR₁—, —S(═O)₂—, a carbonyl group, an alkylenegroup, an alkenylene group, an alkynylene group, —C(═O)—X₁— or—X₁—C(═O)—. In the above, the R₁ may be hydrogen, an alkyl group, analkenyl group, an alkynyl group, an alkoxy group or an aryl group andthe X₁ may be a single bond, an oxygen atom, a sulfur atom, —NR₂—,—S(═O)₂—, an alkylene group, an alkenylene group or alkynylene group,and the R₂ may be hydrogen, an alkyl group, an alkenyl group, an alkynylgroup, an alkoxy group or an aryl group. An appropriate linker may theoxygen atom. The side chain may be linked to the aromatic structure via,for example, an oxygen atom or nitrogen.

In a case where the aromatic structure is linked to the main chain ofthe block as a side chain, the aromatic structure may also be directlylinked to the main chain or may be linked to the main chain via alinker. The linker may be an oxygen atom, a sulfur atom, —S(═O)₂—, acarbonyl group, an alkylene group, an alkenylene group, an alkynylenegroup, —C(═O)—X₁— or —X₁—C(═O)—. In the above, the X₁ may be a singlebond, an oxygen atom, a sulfur atom, —S(═O)₂—, an alkylene group, analkenylene group or alkynylene group. An appropriate linker boding thearomatic structure to the main chain may —C(═O)—O— or —O—C(═O)—, but isnot limited thereto.

In another embodiment, the aromatic structure in the first block and/orthe second block of the block copolymer may include 1 or more, 2 ormore, 3 or more, 4 or more or 5 or more halogen atom(s). The number ofthe halogen atom(s) may be 30 or less, 25 or less, 20 or less, 15 orless or 10 or less. The halogen atom may be a fluorine or chlorine; andthe fluorine may be used. The block comprising the aromatic structureincluding the halogen atom may effectively form the phase separationstructure by an appropriate interaction with the other block.

As the aromatic structure including the halogen atom, an aromaticstructure having 6 to 30, 6 to 25, 6 to 21, 6 to 18 or 6 to 13 carbonatoms may be illustrated, but is not limited thereto.

For realizing appropriate phase separations, in a case where both of thefirst and second block include the aromatic structures, the first blockmay include an aromatic structure that does not include the halogen atomand the second block may include an aromatic structure that includes thehalogen atom. Further, the aromatic structure of the first block mayinclude the side chain that is linked directly or via the linkerincluding the oxygen or nitrogen atom.

In a case where the block copolymer includes the block having the sidechain, the block may be a block represented by, for example, Formula 1.

In Formula 1, the R may be hydrogen or an alkyl group having 1 to 4carbon atom(s), the X may be a single bond, an oxygen atom, a sulfuratom, —S(═O)₂—, a carbonyl group, an alkylene group, an alkenylenegroup, an alkynylene group, —C(═O)—X₁— or —X₁—C(═O)—, wherein the X₁ maybe an oxygen atom, a sulfur atom, —S(═O)₂—, an alkylene group, analkenylene group or an alkynylene group, and the Y may be a monovalentsubstituent including a cyclic structure to which a chain having 8 ormore chain-forming atoms is linked.

The term “single bond” as used herein may refer to a case where there isno atom in a corresponding site. For example, if the X in the Formula 1is the single bond, a structure in which the Y is directly linked to thepolymer chain may be realized.

The term “alkyl group” as used herein may refer to, unless definedotherwise, a linear, a branched or a cyclic alkyl group having 1 to 20,1 to 16, 1 to 12, 1 to 8, or 1 to 4 carbon atoms, and the alkyl groupmay be optionally substituted with at least one substituent. In a casewhere the side chain is the alkyl group, the alkyl group may include 8or more, 9 or more, 10 or more, 11 or more or 12 or more carbon atoms,and the number of the carbon atoms in the alkyl group may be 30 or less,25 or less, 20 or less or 16 or less.

The term “alkenyl or alkynyl group” as used herein may refer to, unlessdefined otherwise, a linear, a branched or a cyclic alkenyl or alkynylgroup having 2 to 20, 2 to 16, 2 to 12, 2 to 8, or 2 to 4 carbon atomsand the alkenyl or alkynyl group may be optionally substituted with atleast one substituent. In a case where the side chain is the alkenyl oralkynyl group, the alkenyl or the alkynyl group may include 8 or more, 9or more, 10 or more, 11 or more or 12 or more carbon atoms, and thenumber of the carbon atoms in the alkenyl or the alkynyl group may be 30or less, 25 or less, 20 or less or 16 or less.

The term “alkylene group” as used herein may refer to, unless definedotherwise, an alkylene group having 1 to 20, 1 to 16, 1 to 12, 1 to 8 or1 to 4 carbon atoms. The alkylene group may have a linear, branched, orcyclic structure, and may be optionally substituted with at least onesubstituent.

The term “alkenylene or alkynylene group” as used herein may refer to,unless defined otherwise, an alkenylene or alkynylene group having 2 to20, 2 to 16, 2 to 12, 2 to 8 or 2 to 4 carbon atoms. The alkenylene oralkynylene group may have a linear, branched, or cyclic structure, andmay be optionally substituted with at least one substituent.

The X of the Formula 1 may be, in another embodiment, —C(═O)O— or—OC(═O)—.

The Y in the formula 1 is the substituent including the chain, it may bea substituent including, for example, an aromatic structure having 6 to18 or 6 to 12 carbon atoms. In the above, the chain may be an alkylgroup having 8 or more, 9 or more, 10 or more, 11 or more or 12 or morecarbon atoms. The alkyl group may include 30 or less, 25 or less, 20 orless or 16 or less carbon atom. The chain may be directly linked to thearomatic structure or be linked to the aromatic structure via the linkeras described above.

The first block may be, in another embodiment, represented by theFormula 2 below.

In Formula 2, the R may be the hydrogen atom or the alkyl group having 1to 4 carbon atom(s), the X may be —C(═O)—O—, the P may be the arylenegroup having 6 to 12 carbon atoms, the Q may be the oxygen atom, the Zis the chain having 8 or more chain-forming atoms.

In another embodiment of the Formula 2, the P may be a phenylene. Also,the Z may be a linear alkyl group having 9 to 20, 9 to 18 or 9 to 16. Ina case where the P is the phenylene, the Q may be linked to the paraposition of the phenylene. The alkyl group, arylene group, phenylenegroup and the chain may be optionally substituted with at least onesubstituent.

In a case where the block copolymer including the block comprising thearomatic structure comprising the halogen atom, the block may be a blockrepresented by Formula 3 below.

In Formula 3, the X₂ may be a single bond, an oxygen atom, a sulfuratom, —S(═O)₂—, an alkylene group, an alkenylene group, an alkynylenegroup, —C(═O)—X₁— or —X₁—C(═O)—, where the X₁ is a single bond, anoxygen atom, a sulfur atom, —S(═O)₂—, an alkylene group, an alkenylenegroup or an alkynylene group, and the W may be an aryl group includingat least one halogen atom.

In another embodiment of the Formula 3, the X₂ may be the single bond orthe alkylene group.

In the Formula 3, the aryl group of the W may be an aryl group having 6to 12 carob atoms or a phenyl group. The aryl group or the phenyl groupmay include 1 or more, 2 or more, 3 or more, 4 or more or 5 or morehalogen atom(s). The number of the halogen atom(s) may be 30 or less, 25or less, 20 or less, 15 or less or 10 or less. As the halogen atom,fluorine atom may be used.

The block of the Formula 3 may be, in another embodiment, represented byFormula 4 below.

In Formula 4, the X₂ is the same as defined in the Formula 3, and the R₁to R₅ may be each independently hydrogen, an alkyl group, a haloalkylgroup or a halogen atom. The number of the halogen atom included in theR₁ to R₅ is 1 or more.

In Formula 4, the R₁ to R₅ may be each independently hydrogen, an alkylgroup having 1 to 4 carbon atom(s) or a haloalkyl group having 1 to 4carbon atom(s) or the halogen atom, and the halogen atom may be thefluorine or chlorine.

In Formula 4, the R₁ to R₅ may include 1 or more, 2 or more, 3 or more,4 or more, 5 or more or 6 or more halogen atom(s). The upper limit ofthe number of the halogen atom(s) is not particularly limited, and thenumber of the halogen atom(s) in the R₁ to R₅ may be, for example, 12 orless, 8 or less, or 7 or less.

The block copolymer may include only the above described two kinds ofblocks or may include one or both of the above described two kinds ofblocks along with another block.

A method for preparing the block copolymer is not particularly limited.For example, the block copolymer may be prepared by a living radicalpolymerization (LRP). For example, there are methods such as the anionicpolymerization, in which block copolymers are synthesized in thepresence of inorganic acid salts such as salts of alkali metal or alkaliearth metal by using organic rare earth metal complexes or organicalkali metal compounds as polymerization initiators; the anionicpolymerization, in which block copolymers are synthesized in thepresence of organic aluminum compounds by using organic alkali metalcompounds as polymerization initiators; the atom-transfer radicalpolymerization (ATRP) using an atom transfer radical polymerizer as apolymerization controller; the activators regenerated by electrontransfer (ATGET) ATRP performing polymerization in the presence of anorganic or inorganic reducing agent generating electrons using an atomtransfer radical polymerizer as a polymerization controller; theinitiators for continuous activator regeneration (ICAR) ATRP; thereversible addition-ring opening chain transfer (RAFT) polymerizationusing an inorganic reducing agent reversible addition-ring opening chaintransfer agent; and the a method using an organic tellurium compound asan initiator, and an appropriate method may be selected among the abovemethods.

In one embodiment, the block copolymer may be prepared by a methodincluding polymerizing a material comprising monomers capable of formingthe block in the presence of radical initiators and living radicalpolymerization reagents by the living radical polymerization. The methodfor preparing the block copolymer may further include, for example,precipitating the polymerized product formed from the above process innon solvent.

A kind of the radical initiators may be suitably selected inconsideration of polymerization efficiency without particularlimitation, and an azo compound such as azobisisobutyronitrile (AIBN) or2,2′-azobis-(2,4-dimethylvaleronitrile), or a peroxide compound such asbenzoyl peroxide (BPO) or di-t-butyl peroxide (DTBP) may be used.

The LRP may be performed in a solvent such as methylenechloride,1,2-dichloroethane, chlorobenzene, dichlorobenzene, benzene, toluene,acetone, chloroform, tetrahydrofuran, dioxane, monoglyme, diglyme,dimethylformamide, dimethylsulfoxide or dimethylacetamide.

As the non-solvent, for example, an alcohol such as methanol, ethanol,normal propanol or isopropanol, a glycol such as ethyleneglycol, or anether compound such as n-hexane, cyclohexane, n-heptane or petroleumether may be used without limitation.

The block copolymer as described above exhibits an excellent phaseseparation property and self assembling property and its verticalaligning property is also excellent. The present inventor has confirmedthat, if the block copolymer further satisfies at least one parameteramong ones as described below, the above properties can be furtherimproved.

For example, the block copolymer may form a layer showing an in-planephase diffraction pattern of the grazing incidence small angle X rayscattering (GISAXS) on a hydrophobic surface. The block copolymer mayform a layer showing an in-plane phase diffraction pattern of thegrazing incidence small angle X ray scattering (GISAXS) on a hydrophilicsurface.

The term “showing the in-plane phase diffraction pattern of the grazingincidence small angle X ray scattering (GISAXS)” as used herein mayrefer to a case where a peak vertical to the X coordinate is observed inthe GISAXS diffraction pattern when the GISAXS analysis is performed.Such a peak may be confirmed by the vertical aligning property of theblock copolymer. Therefore, the block copolymer showing the in-planephase diffraction pattern shows the vertical aligning property. Further,if the above peaks are observed with a regular interval, the phaseseparation efficiency may be further improved.

The term “vertical” as used herein is a term considering errors and, forexample, it may include errors within ±10 degrees, ±8 degrees, ±6degrees, ±4 degrees or ±2 degrees.

A block copolymer capable of forming a layer showing the in-plane phasediffraction patterns on both of the hydrophobic and the hydrophilicsurfaces can show the vertical aligning property on various surface towhich any treatment for inducing the vertical aligning is not performed.The term “hydrophobic surface” as used herein may refer to a surface ofwhich a wetting angle of purified water is in a range from 5 degrees to20 degrees. Examples of the hydrophobic surface may include a surface ofsilicone treated with the piranha solution, sulfuric acid, or an oxygenplasma, but is not limited thereto. The term “hydrophilic surface” asused herein may refer to a surface of which a wetting angle of purifiedwater is in a range from 50 degrees to 70 degrees. Examples of thehydrophilic surface may include a surface of silicone treated withhydrogen fluoride, silicone treated with hexamethyldisilazane orpolydimethylsiloxane treated with oxygen plasma, but is not limitedthereto.

Unless defined otherwise, in this document, a property such as a wettingangle that can be changed according to temperature is measured at roomtemperature. The term “room temperature” as used herein may refer to atemperature in its natural state that is not heated and cooled and mayrefer to a temperature in a range from about 10° C. to 30° C., or ofabout 25° C. or about 23° C.

The layer that is formed on the hydrophobic or hydrophilic surface andshows the in-plane phase diffraction pattern on the GISAXS may be alayer to which a thermal annealing is performed. In one embodiment, thelayer for measuring the GISAXS is, for example, prepared by coating acoating solution, which is prepared by diluting the block copolymer in asolvent (for example, fluorobenzene) to a concentration of about 0.7weight %, on a corresponding hydrophobic or hydrophilic surface so asfor the coated layer to have a thickness of about 25 nm and an area ofabout 2.25 cm² (a width: 1.5 cm, a length: 1.5 cm) and then performedthe thermal annealing thereto. The thermal annealing may be performed bymaintaining the layer for about 1 hour at a temperature of 160° C. TheGISAXS may be measured by irradiating the above prepared layer with Xray so as for an incident angle thereof to be in a range from 0.12 to0.23 degrees. Diffraction patterns scattered from the layer may beobtained by a conventional measuring device (for example, 2D marCCD).Techniques confirming the existence of the in-plane phase diffractionpattern from the above obtained diffraction pattern is known in thefield.

The block copolymer showing the above peaks in the GISAXS can showexcellent self assembling property and the property can be effectivelycontrolled according to an object.

In another embodiment, the block copolymer may exhibit at least one peakwithin a predetermined range of the scattering vector (q) in the XRD (Xray diffraction) analysis as described above.

For example, in the XRD analysis, the block copolymer may show at leastone peak within a range from 0.5 nm⁻¹ to 10 nm⁻¹ of the scatteringvectors (the q values). In other embodiment, the range of the scatteringvectors (the q values) within which the at least one peak is observedmay be from 0.7 nm⁻¹ or more, 0.9 nm⁻¹ or more, 1.1 nm⁻¹ or more, 1.3nm⁻¹ or more or 1.5 nm⁻¹ or more. In other embodiment, the range of thescattering vectors (the q values) within which the at least one peak isobserved may be from 9 nm⁻¹ or less, 8 nm⁻¹ or less, 7 nm⁻¹ or less, 6nm⁻¹ or less, 5 nm⁻¹ or less, 4 nm⁻¹ or less, 3.5 nm⁻¹ or less or 3 nm⁻¹or less.

The FWHM (full width at half maximum) of the peak observed within theabove range of the scattering vectors (q) may be from 0.2 nm⁻¹ to 0.9nm⁻¹. In another embodiment, the FWHM may be 0.25 nm⁻¹ or more, 0.3 nm⁻¹or more or 0.4 nm⁻¹ or more. The FWHM may be, in another embodiment,0.85 nm⁻¹ or less, 0.8 nm⁻¹ or less or 0.75 nm⁻¹ or less.

The term “FWHM (full width at half maximum)” as used herein may refer toa width (difference between scattering vectors (q's)) of a peak showingan intensity half times as large as the maximum intensity. The methodforming the FWHM is as described above.

The scattering vector (q) and the FWHM are values obtained from anumerical analysis to which the least square technique is used, withrespect to results of the XRD analysis as described below. In the abovemethod, the Gaussian fitting is performed with respect to a profile ofpeaks in the XRD pattern under a state where a position at which a XRDdiffraction pattern has a lowest intensity becomes a baseline and thelowest intensity is converted to zero, and then the scattering vector(q) and the FWHM are obtained from the result of the Gaussian fitting.The R square of the Gaussian fitting is at least 0.9 or more, 0.92 ormore, 0.94 or more or 0.96 or more. The method obtaining the aboveinformation from the XRD analysis is known, and, for example, anumerical value analysis program such as the origin may be used.

The block copolymer showing the peak having the above FWHM within theabove range of scattering vectors (q's) may include a crystallineportion suitable for the self assembling. The block copolymer showingthe peak having the above FWHM within the above range of scatteringvectors (q's) may show an excellent self assembling property.

The XRD analysis may be performed by passing X-ray through a sample ofthe block copolymer and then measuring a scattering intensity accordingto scattering vector. The XRD analysis may be performed with respect toa block copolymer without any specific pre-treatment, and, for example,it may be performed by drying the block copolymer under an appropriatecondition and then passing X ray through it. As the X ray, X ray, avertical size of which is 0.023 mm and a horizontal size of which is 0.3mm can be used. By using a measuring device (for example, 2D marCCD), a2D diffraction pattern scattered from the sample is obtained as animage, and then the above fitting is performed with respect to theobtained diffraction pattern so as to obtain the scattering vector andthe FWHM, and the like.

As described below, in a case where at least one block of the blockcopolymer includes the side chain, the number (n) of the chain-formingatoms and the scattering vector (q) obtained from the XRD analysis maysatisfy the equation 1 below.

3 nm⁻¹˜5 nm⁻¹ =nq/(2×π)  [Equation 1]

In the Equation 1, the “n” is the number of the chain-forming atoms, andthe “q” is the smallest scattering vector among scattering vectors atwhich peaks are observed in the XRD analysis or a scattering vector atwhich a peak having the largest area is observed. Further, the π in theequation 1 is the ratio of the circumference of a circle to itsdiameter.

The scattering vector and the like substituted with the equation 1 canbe obtained according to a method as described in the XRD analysismethod.

The scattering value substituted with the value of the equation 1 may bea scattering value within a range from 0.5 nm⁻¹ to 10 nm⁻¹. In anotherembodiment, the scattering value substituted with the value of theequation 1 may be a scattering value within a range from 0.5 nm⁻¹ to 10nm⁻¹. In another embodiment, the scattering value substituted with thevalue of the equation 1 may be 0.7 nm⁻¹ or more, 0.9 nm⁻¹ or more, 1.1nm⁻¹ or more, 1.3 nm⁻¹ or more or 1.5 nm⁻¹ or more. In anotherembodiment, the scattering value substituted with the value of theequation 1 may be 9 nm⁻¹ or less, 8 nm⁻¹ or less, 7 nm⁻¹ or less, 6 nm⁻¹or less, 5 nm⁻¹ or less, 4 nm⁻¹ or less, 3.5 nm⁻¹ or less or 3 nm⁻¹ orless.

The equation 1 may represent a relation between the number of thechain-forming atoms and an interval (D) between blocks including thechains under a state where the block copolymer is self assembled andforms the phase separated structure. If the number of the chain-formingatoms of the block copolymer including the chains satisfies the equation1, the crystallizability exhibited by the chain is improved, andtherefore the phase separation property and the vertical aligningproperty may be largely improved. In another embodiment, the nq/(2×π) inthe equation 1 may be 4.5 nm⁻¹ or less. In the above, the interval (D,unit: nm) between blocks including the chains can be calculated by anumerical formula, D=2×π/q. In the above, the “D” is the interval (D,unit: nm) between the blocks and the it and the q are the same asdefined in the equation 1.

In the block copolymer, one of the first and the second blocks may havea volume fraction is in a range from 0.4 to 0.8 and the other block mayhave a volume fraction in a range from 0.2 to 0.6. In a case where theblock copolymer comprises the side chain, the block having the sidechain may have the volume fraction from 0.4 to 0.8. For example, if thefirst block comprises the side chain, the first block may have thevolume fraction from 0.4 to 0.8 and the second block may have the volumefraction in a range from 0.2 to 0.6. Further, as described below, if thefirst block comprises an aromatic structure that does not have a halogenatom and the second block comprises an aromatic structure that has thehalogen atom, the first block may have the volume fraction from 0.4 to0.8 and the second block may have the volume fraction in a range from0.2 to 0.6. The sum of the volume fractions of the first and the secondblocks may be 1. The block copolymer including each block in the abovevolume fractions may show an excellent self assembling property and thephase separation property, and the vertical aligning property can beconfirmed. The volume fraction of each block of the block copolymer maybe obtained by using the density of each block and a molecular weightobtained by the Gel Permeation Chromatograph (GPC).

In the block copolymer, an absolute value of a difference betweendensities of the first and the second blocks may be 0.25 g/cm³ or more,0.3 g/cm³ or more, 0.35 g/cm³ or more, 0.4 g/cm³ or more or 0.45 g/cm³or more. The absolute value of the difference between the densities maybe 0.9 g/cm³ or less, 0.8 g/cm³ or less, 0.7 g/cm³ or less, 0.65 g/cm³or less or 0.6 g/cm³ or less. The structure in which the first and thesecond blocks, the absolute value of the difference between thedensities of which is within the above range, are linked via thecovalent bond may realize an effective microphase separation by a phaseseparation due to appropriate un-compatibilities.

The density of each block in the block copolymer may be obtained througha known buoyancy method. For example, it may be obtained by analyzing amass of a block copolymer in solvent such as ethanol, of which a massand a density in the air are known.

In a case where the block copolymer comprises the above described sidechain, the block comprising the chain may have a lower density than theother block. For example, if the first block comprises the chain, thefirst block may have a lower density than the second block. In thiscase, the density of the first block may be in a range from about 0.9g/cm³ to about 1.5 g/cm³. In another embodiment, the density of thefirst block may be about 0.95 g/cm³ or more. The density of the firstblock may be about 1.4 g/cm³ or less, about 1.3 g/cm³ or less, about 1.2g/cm³ or less, about 1.1 g/cm³ or less or about 1.05 g/cm³ or less. Sucha block copolymer including the above first block and showing the abovedifference between the densities of blocks may show an excellent selfassembling property. The surface energy and the density are measured atthe room temperature.

The block copolymer may have, for example, a number average molecularweight (Mn) in a range from approximately 3,000 to 300,000. The term“number average molecular weight” as used herein may refer to aconverted value with respect to the standard polystyrene measured by theGPC (Gel Permeation Chromatography). Unless defined otherwise, the term“molecular weight” as used herein may refer to the number averagemolecular weight. The molecular weight (Mn), in another embodiment, maybe, for example, 3000 or more, 5000 or more, 7000 or more, 9000 or more,11000 or more, 13000 or more or 15000 or more. The molecular weight(Mn), in another embodiment, may be, for example, 250000 or less, 200000or less, 180000 or less, 160000 or less, 140000 or less, 120000 or less,100000 or less, 90000 or less, 80000 or less, 70000 or less, 60000 orless, 50000 or less, 40000 or less, 30000 or less, or 25000 or less. Theblock copolymer may have the polydispersity (Mw/Mn) in a range from 1.01to 1.60. In another embodiment, the polydispersity may be about 1.1 ormore, about 1.2 or more, about 1.3 or more, or about 1.4 or more.

In the above range, the block copolymer may exhibit an appropriate selfassembling property. The number average molecular weight and the like ofthe block copolymer may be controlled considering the objected selfassembled structure.

If the block copolymer at least includes the first and second blocks, aratio of the first block, for example, the block including the chain inthe block copolymer may be in a range of 10 mole % to 90 mole %.

The present application relates to a polymer layer including the blockcopolymer. The polymer layer may be used in various applications. Forexample, it can be used in a biosensor, a recording media such as aflash memory, a magnetic storage media or the pattern forming method oran electric device or an electronic device, and the like.

In one embodiment, the block copolymer in the polymer layer may beforming a periodic structure including a sphere, a cylinder, a gyroid,or a lamella by the self assembly. For example, in one segment of thefirst block or the second block or other block linked to the above blockvia a covalent bond in the block copolymer, other segment may be formingthe regular structure such as lamella form, cylinder form and the like.And the above structure may be aligned vertically.

The polymer layer may show the above in-plane phase diffraction pattern,i.e., the peak vertical to the X coordinate in the GISAXS diffractionpattern of the GISAXS analysis. In further embodiment, two or more peaksmay be observed in the X coordinate of the GISAXS diffraction pattern.In a case where two or more peaks are observed, the scattering vectors(the q values) may be confirmed with having constant ratios.

The present application relates also to a method for forming a polymerlayer by using the block copolymer. The method may include forming apolymer layer including the block copolymer on a substrate in aself-assembled state. For example, the method may include forming alayer of the block copolymer or a coating solution in which the blockcopolymer is diluted in suitable solvent on the substrate by a coatingand the like, and if necessary, then aging or heat-treating the layer.

The aging or the heat treatment may be performed based on, for example,a phase transition temperature or glass transition temperature of theblock copolymer, and for example, may be performed at a temperaturehigher than the glass transition temperature or phase transitiontemperature. A time for the heat treatment is not particularly limited,and the heat treatment may be performed for approximately 1 minute to 72hours, but may be changed if necessary. In addition, the temperature ofthe heat treatment of the polymer layer may be, for example, 100° C. to250° C., but may be changed in consideration of the block copolymer usedherein.

The formed layer may be aged in a non-polar solvent and/or a polarsolvent at the room temperature for approximately 1 minute to 72 hours.

The present application relates also to a pattern-forming method. Themethod may include selectively removing the first or second block of theblock copolymer from a laminate comprising a substrate and a polymerlayer that is formed on a surface of the substrate and that includes aself-assembled block copolymer. The method may be a method for forming apattern on the above substrate. For example, the method may includeforming the polymer layer on the substrate, selectively removing oneblock or two or more blocks of the block copolymer that is in thepolymer layer; and then etching the substrate. By the above method, forexample, nano-scaled micropattern may be formed. Further, according toshapes of the block copolymer in the polymer layer, various shapes ofpattern such as nano-rod or nano-hole can be formed by the above method.If necessary, in order to form a pattern, the block copolymer may bemixed with another copolymer or homopolymer. A kind of the substrateapplied to this method may be selected without particular limitation,and, for example, silicon oxide and the like may be applied.

For example, according to the method, a nano-scale pattern of siliconoxide having a high aspect ratio may be formed. For example, varioustypes of patterns such as a nanorod or nanohole pattern may be formed byforming the polymer layer on the silicon oxide, selectively removing anyone block of the block copolymer in a state where the block copolymer inthe polymer layer is formed in a predetermined structure, and etchingthe silicon oxide in various methods, for example, reactive ion etching.In addition, according to the above method, a nano pattern having a highaspect ratio can be formed.

For example, the pattern may be formed to a scale of several tens ofnanometers, and such a pattern may be applied in various uses includinga next-generation information electronic magnetic recording medium.

For example, a pattern in which nano structures, for example, nanowires,having a width of approximately 3 to 40 nm are disposed at an intervalof approximately 6 to 80 nm may be formed by the above-described method.In another embodiment, a structure in which nanoholes having a width,for example, a diameter of approximately 3 to 40 nm are disposed at aninterval of approximately 6 to 80 nm can be implemented.

In addition, in this structure, nanowires or nanoholes may be formed tohave a high aspect ratio.

In this method, a method of selectively removing any one block of theblock copolymer is not particularly limited, and for example, a methodof removing a relatively soft block by irradiating a suitableelectromagnetic wave, for example, ultra violet rays to a polymer layermay be used. In this case, conditions for ultra violet radiation may bedetermined according to a type of the block of the block copolymer, andultra violet rays having a wavelength of approximately 254 nm may beirradiated for 1 to 60 minutes.

In addition, followed by the ultra violet radiation, the polymer layermay be treated with an acid to further remove a segment degraded by theultra violet rays.

In addition, the etching of the substrate using the polymer layer fromwhich a block is selectively removed may be performed by reactive ionetching using CF₄/Ar ions, and followed by the above process, andremoving the polymer layer from the substrate by oxygen plasma treatmentmay be further performed.

BRIEF DESCRIPTION OF FIGURES

FIGS. 1 to 6 show SEM images of polymer layers.

FIGS. 7 to 11 show GISAXS diffraction pattern.

FIGS. 13 to 14 show SEM images of polymer layers.

EFFECTS

The present application may provide the block copolymers that haveexcellent self assembling and phase separation properties and thereforethat can be effectively used in various applications. The presentapplication may also provide applications of the block copolymers.

ILLUSTRATIVE EMBODIMENTS

Hereinafter, the present application will be described in detail withreference to Examples and Comparative Examples, but the scope of thepresent application is not limited to the following examples.

1. NMR Analysis

The NMR analysis was performed at the room temperature by using a NMRspectrometer including a Varian Unity Inova (500 MHz) spectrometerhaving a triple resonance 5 mm probe. A sample to be analyzed was usedafter diluting it in solvent (CDCl₃) for the NMR analysis to aconcentration of approximately 10 mg/ml and a chemical shift (δ) wasexpressed in ppm.

<Abbreviation>

br=wide signal, s=singlet, d=doublet, dd=double doublet, t=triplet,dt=double triplet, q=quadruplet, p=quintuplet, m=multiplet

2. GPC (Gel Permeation Chromatograph)

The number average molecular weight and the polydispersity were measuredby the GPC (Gel Permeation Chromatograph). In a 5 mL vial, a blockcopolymer or a macroinitiator to be measured of Example or ComparativeExample and then diluted to a concentration of about 1 mg/mL. Then, thestandard sample for a calibration and a sample to be analyzed werefiltered by a syringe filter (pore size: 0.45 μm) and then analyzed.ChemStation from the Agilent technologies, Co. was used as an analysisprogram. The number average molecular weight (Mn) and the weight averagemolecular weight (Mw) were obtained by comparing an elution time of thesample with a calibration curve and then the polydispersity (PDI) wasobtained from their ratio (Mw/Mn). The measuring condition of the GPCwas as below.

<GPC Measuring Condition>

Device: a 1200 series from Agilent technologies, Co.

Column: two of PLgel mixed B from Polymer laboratories, Co. were used

Solvent: THF

Temperature of the column: 35° C.

Concentration of Sample: 1 mg/mL, 200 L injection

Standard Sample: Polystyrene (Mp: 3900000, 723000, 316500, 52200, 31400,7200, 3940, 485)

3. GISAXS (Grazing Incidence Small Angle X Ray Scattering)

The GISAXS analysis was performed in a 3 C beam line of the Pohang LightSource. A coating solution was prepared by dissolving a block copolymerto be evaluated in fluorobenzene so as for a solid content to be 0.7weight %, the coating solution was spin coated on a substrate so as tohaving a thickness of about 5 nm. The coating area was controlled to beabout 2.25 cm² (coated area: width=1.5 cm, length=1.5 cm). The coatedlayer was dried for about 1 hour at the room temperature and thensubjected to the thermal annealing at about 160° C. for about 1 hour soas for the phase separation structure to be realized. Therefore, thelayer in which the phase separation structure was realized was formed.The formed layer was irradiated with X ray so as for an incident angleto be from about 0.12 degrees to 0.23 degrees, which corresponded to anangle between a critical angle of the layer and a critical angle of thesubstrate, and then the X ray diffraction pattern scattered from thelayer was obtained by using a 2D marCCD. At this time, a distance fromthe layer to the detector was selected so as for the self assembledpattern in the layer to be effectively observed within a range fromabout 2 m to 3 m. As the substrate, a substrate (a silicone substratethat was treated with piranha solution and that has a wetting angle ofabout 5 degrees with respect to purified water at the room temperature)having the hydrophilic surface or a substrate (a silicone substrate thatwas treated with HMDS (hexamethyldisilazane) and that has a wettingangle of about 60 degrees with respect to purified water at the roomtemperature) having the hydrophobic surface was used.

4. XRD Analysis

The XRD pattern was evaluated by measuring the scattering intensityaccording to the scattering vector (q) by passing X ray through a samplein a 4 C beam line of the Pohang Light Source. As the sample, powderobtained from the block copolymer to which any specific pre-treatmentwas not performed by purifying it so as to remove impurities therefromwas used after putting it in a cell for measurement of the XRD. Duringthe XRD pattern analysis, as the X ray, X ray, a vertical size of whichis 0.023 mm and a horizontal size of which is 0.3 mm was used and, asthe detector, the measuring device (for example, 2D marCCD) was used. A2D diffraction pattern scattered from the sample was obtained as animage. Information such as the scattering vectors and the FWHMs wasobtained by analyzing the obtained diffraction pattern by the numericalanalysis using the least square technique. The analysis was performed bythe origin program. A position at which the XRD diffraction pattern hadthe lowest intensity became the baseline and the lowest intensity wasconverted to zero, and then the Gaussian fitting was performed withrespect to the profile of peaks in the XRD pattern, and then thescattering vector (q) and the FWHM were obtained from the result of theGaussian fitting. The R square of the Gaussian fitting was set to be0.96 or more.

5. Surface Energies Measurement

The surface energy was measured by using the drop shape analyzer (DSA100 product from KRUSS, Co.). The surface energy was evaluated withrespect to the polymer layer formed by spin-coating a coating solution,which was prepared by dissolving the material to be evaluated influorobenzene so as for a solid content to be 2 weight %, on a siliconewafer so as for the coated layer to have a thickness of 50 nm (coatedarea: width=2 cm, length=2 cm) and drying it for about 1 hour at theroom temperature and then subjecting it to the thermal annealing atabout 160° C. for about 1 hour. A process, in which deinonized water ofwhich the surface tension is known was dropped on the layer after thethermal annealing and then its contact angle was obtained, was repeated5 times, and an average value of the obtained 5 contact angles wascalculated. Identically, a process, in which diiodomethane of which thesurface tension is known was dropped on the layer after the thermalannealing and then its contact angle was obtained, was repeated 5 times,and an average value of the obtained 5 contact angles was calculated.The surface energy was obtained by the Owens-Wendt-Rabel-Kaelble methodby using the obtained average values of the contact angles of thedeionized water and the diiodomethane and substituting a value (theStrom value) regarding the surface tension of solvent. The surfaceenergy of each block of the block copolymer was obtained as above withrespect to a homopolymer prepared only by monomers forming the block.

6. Volume Fraction Measurement

The volume fraction of each block of the block copolymer was calculatedbased on a molecular weight measured by a GPC (Gel PermeationChromatograph) and the density at the room temperature. In the above,the density was measured by the buoyancy method, specifically, wascalculated by a mass of a sample to be measured in solvent (ethanol), ofwhich a mass and a density in the air are known.

Preparation Example 1 Synthesis of a Monomer (A)

A compound (DPM-C12) of the Formula A below was synthesized by the belowmethod. To a 250 mL flask, hydroquinone (10.0 g, 94.2 mmole) and1-bromododecane (23.5 g, 94.2 mmole) were added and dissolved in 100 mLacetonitrile, an excessive amount of potassium carbonate was addedthereto and then the mixture was reacted at 75° C. for approximately 48hours under nitrogen. After the reaction, remaining potassium carbonateand acetonitrile used for the reaction were removed. The work up wasperformed by adding a mixed solvent of dichloromethane (DCM) and water,and separated organic layers were collected and dehydrated throughMgSO₄. Subsequently, a white solid intermediate was obtained with ayield of approximately 37% using DCM through column chromatography.

<NMR Analysis Result of the Intermediate>

¹H-NMR (CDCl₃): δ6.77 (dd, 4H); 54.45 (s, 1H); δ3.89 (t, 2H); δ1.75 (p,2H); δ1.43 (p, 2H); δ1.33-1.26 (m, 16H); δ0.88 (t, 3H)

The synthesized intermediate (9.8 g, 35.2 mmole), methacrylic acid (6.0g, 69.7 mmole), dicyclohexylcarbodiimide (DCC; 10.8 g, 52.3 mmole) andp-dimethylaminopyridine (DMPA; 1.7 g, 13.9 mmol) were put into a flask,120 ml of methylenechloride was added, and a reaction was performed atthe room temperature for 24 hours under nitrogen. After the reaction wascompleted, a urea salt produced in the reaction was removed through afilter, and remaining methylenechloride was also removed. Impuritieswere removed using hexane and DCM (dichloromethane) as mobile phasesthough column chromatography, and the obtained product wasrecrystallized in a mixed solvent of methanol and water (mixed in 1:1weight ratio), thereby obtaining a white solid product (DPM-C12)(7.7 g,22.2 mmol) with a yield of 63%.

<NMR Analysis Result>

¹H-NMR (CDCl₃): δ7.02 (dd, 2H); δ6.89 (dd, 2H); δ6.32 (dt, 1H); δ5.73(dt, 1H); δ3.94 (t, 2H); δ2.05 (dd, 3H); δ1.76 (p, 2H); δ1.43 (p, 2H);1.34-1.27 (m, 16H); δ0.88 (t, 3H)

In the above, the R is a linear alkyl having 12 carbon atoms.

Preparation Example 2 Synthesis of a Monomer (G)

A compound of the Formula G below was synthesized according to themethod of Preparation Example 1, except that 1-bromobutane was usedinstead of the 1-bromododecane. The NMR analysis result with respect tothe above compound is as below.

<NMR Analysis Result with Respect to DPM-C4>

¹H-NMR (CDCl₃): δ7.02 (dd, 2H); δ6.89 (dd, 2H); δ6.33 (dt, 1H); δ5.73(dt, 1H); δ3.95 (t, 2H); δ2.06 (dd, 3H); δ1.76 (p, 2H); δ1.49 (p, 2H);δ0.98 (t, 3H)

In the above, the R is a linear alkyl having 4 carbon atoms.

Preparative Example 3 Synthesis of a Monomer (B)

A compound of the Formula B below was synthesized according to themethod of Preparation Example 1, except that 1-bromooctane was usedinstead of the 1-bromododecane. The NMR analysis result with respect tothe above compound is as below.

<NMR Analysis Result with Respect to DPM-C8>

¹H-NMR (CDCl₃): δ7.02 (dd, 2H); δ6.89 (dd, 2H); δ6.32 (dt, 1H); δ5.73(dt, 1H); δ3.94 (t, 2H); δ2.05 (dd, 3H); δ1.76 (p, 2H); δ1.45 (p, 2H);1.33-1.29 (m, 8H); δ0.89 (t, 3H)

In the above, the R is a linear alkyl having 8 carbon atoms.

Preparation Example 4 Synthesis of a Monomer (C)

A compound (DPM-C10) of the Formula C below was synthesized according tothe method of Preparation Example 1, except that 1-bromodecane was usedinstead of the 1-bromododecane. The NMR analysis result with respect tothe above compound is as below.

<NMR Analysis Result with Respect to DPM-C10>

¹H-NMR (CDCl₃): δ7.02 (dd, 2H); δ6.89 (dd, 2H); δ6.33 (dt, 1H); δ5.72(dt, 1H); δ3.94 (t, 2H); δ2.06 (dd, 3H); δ1.77 (p, 2H); δ1.45 (p, 2H);1.34-1.28 (m, 12H); δ0.89 (t, 3H)

In the above, the R is a linear alkyl having 10 carbon atoms.

Preparation Example 5 Synthesis of a Monomer (D)

A compound of the Formula D below was synthesized according to themethod of Preparation Example 1, except that 1-bromotetradecane was usedinstead of the 1-bromododecane. The NMR analysis result with respect tothe above compound is as below.

<NMR Analysis Result with Respect to DPM-C14>

¹H-NMR (CDCl₃): δ7.02 (dd, 2H); δ6.89 (dd, 2H); δ6.33 (dt, 1H); δ5.73(dt, 1H); δ3.94 (t, 2H); δ2.05 (dd, 3H); δ1.77 (p, 2H); δ1.45 (p, 2H);1.36-1.27 (m, 20H); δ0.88 (t, 3H.)

In the above, the R is a linear alkyl having 14 carbon atoms.

Preparation Example 6 Synthesis of a Monomer (E)

A compound of the Formula E below was synthesized according to themethod of Preparation Example 1, except that 1-bromohexadecane was usedinstead of the 1-bromododecane. The NMR analysis result with respect tothe above compound is as below.

<NMR Analysis Result with Respect to DPM-C16>

¹H-NMR (CDCl₃): δ7.01 (dd, 2H); δ6.88 (dd, 2H); δ6.32 (dt, 1H); δ5.73(dt, 1H); δ3.94 (t, 2H); δ2.05 (dd, 3H); δ1.77 (p, 2H); δ1.45 (p, 2H);1.36-1.26 (m, 24H); δ0.89 (t, 3H)

In the above, the R is a linear alkyl having 16 carbon atoms.

Example 1

2.0 g of the compound (DPM-C12) of Preparation Example 1, 64 mg of RAFT(Reversible Addition-Fragmentation chain transfer) reagent(cyanoisopropyl dithiobenzoate), 23 mg of AIBN (azobisisobutyronitrile)and 5.34 mL of benzene were added to a 10 mL flask and then were stirredat the room temperature for 30 minutes and then the RAFT (reversibleaddition fragmentation chain transfer) polymerization was performed at70° C. for 4 hours. After the polymerization, the reacted solution wasprecipitated in 250 mL of methanol that was an extraction solvent, wasvacuum filtered and dried so as to obtain pink macroinitiator. The yieldof the macroinitiator was about 86%, and its number average molecularweight (Mn) and polydispersity (Mw/Mn) were 9,000 and 1.16,respectively.

0.3 g of the macroinitiator, 2.7174 g of pentafluorostyrene and 1.306 mLof benzene were added to a 10 mL Schlenk flask and then were stirred atthe room temperature for 30 minutes and then the RAFT (reversibleaddition fragmentation chain transfer) polymerization was performed at115° C. for 4 hours. After the polymerization, the reacted solution wasprecipitated in 250 mL of methanol that was an extraction solvent, wasvacuum filtered and dried so as to obtain light pink block copolymer.The yield of the block copolymer was about 18%, and its number averagemolecular weight (Mn) and polydispersity (Mw/Mn) were 16,300 and 1.13,respectively. The block copolymer includes the first block derived fromthe monomer (A) of Preparation Example 1 and the second block derivedfrom the pentafluorostyrene.

Example 2

A block copolymer was prepared by the same method as in Example 1 exceptthat a macroinitiator prepared by using the monomer (B) of PreparationExample 3 instead of the monomer (A) of Preparation Example 1 andpentafluorostyrene were used. The block copolymer includes the firstblock derived from the monomer (B) of Preparation Example 3 and thesecond block derived from the pentafluorostyrene.

Example 3

A block copolymer was prepared by the same method as in Example 1 exceptthat a macroinitiator prepared by using the monomer (C) of PreparationExample 4 instead of the monomer (A) of Preparation Example 1 andpentafluorostyrene were used. The block copolymer includes the firstblock derived from the monomer (C) of Preparation Example 4 and thesecond block derived from the pentafluorostyrene.

Example 4

A block copolymer was prepared by the same method as in Example 1 exceptthat a macroinitiator prepared by using the monomer (D) of PreparationExample 5 instead of the monomer (A) of Preparation Example 1 andpentafluorostyrene were used. The block copolymer includes the firstblock derived from the monomer (D) of Preparation Example 5 and thesecond block derived from the pentafluorostyrene.

Example 5

A block copolymer was prepared by the same method as in Example 1 exceptthat a macroinitiator prepared by using the monomer (E) of PreparationExample 6 instead of the monomer (A) of Preparation Example 1 andpentafluorostyrene were used. The block copolymer includes the firstblock derived from the monomer (E) of Preparation Example 6 and thesecond block derived from the pentafluorostyrene.

Comparative Example 1

A block copolymer was prepared by the same method as in Example 1 exceptthat a macroinitiator prepared by using the monomer (G) of PreparationExample 2 instead of the monomer (A) of Preparation Example 1 andpentafluorostyrene were used. The block copolymer includes the firstblock derived from the monomer (G) of Preparation Example 2 and thesecond block derived from the pentafluorostyrene.

Comparative Example 2

A block copolymer was prepared by the same method as in Example 1 exceptthat a macroinitiator prepared by using 4-methoxyphenyl methacrylateinstead of the monomer (A) of Preparation Example 1 andpentafluorostyrene were used. The block copolymer includes the firstblock derived from the 4-methoxyphenyl methacrylate and the second blockderived from the pentafluorostyrene.

Comparative Example 3

A block copolymer was prepared by the same method as in Example 1 exceptthat a macroinitiator prepared by using dodecyl methacrylate instead ofthe monomer (A) of Preparation Example 1 and pentafluorostyrene wereused. The block copolymer includes the first block derived from thedodecyl methacrylate and the second block derived from thepentafluorostyrene.

The GPC results regarding the macroinitiator and the block copolymer ofthe Examples are stated in Table 1.

TABLE 1 Examples Com. Examples 1 2 3 4 5 1 2 3 MI Mn 9000 9300 8500 87009400 9000 7800 8000 PDI 1.16 1.15 1.17 1.16 1.13 1.16 1.17 1.19 BCP Mn16300 19900 17100 17400 18900 18800 18700 16700 PDI 1.13 1.20 1.19 1.171.17 1.22 1.25 1.18 MI: the macroinitiator BCP: the block copolymer Mn:the number average molecular weight PDI: the polydispersity

Test Example 1 Surface Energies Measurement

The surface energies evaluated with respect to each copolymer asprepared above are illustrated in the Table 2 below.

TABLE 2 Examples Com. Examples 1 2 3 4 5 1 2 3 The first blcok SE 30.8331.46 27.38 26.924 27.79 37.37 48.95 19.1 The second block SE 24.4 24.424.4 24.4 24.4 24.4 24.4 24.4 Diff. of SE 6.43 7.06 2.98 2.524 3.3912.98 24.55 5.3 SE: the surface energy (unit: mN/m) Diff. of SE: theabsolute value of the difference between surface energies of the firstblock and the second block

Test Example 2 Self Assembling Property Measurement

The self assembled polymer layer was obtained by spin coating a coatingsolution prepared by dissolving the block copolymer of Examples orComparative Examples in fluorobenzene to a solid content of about 0.7weight % on a silicone wafer so as for a coated thickness to be 5 nm (acoated area: a width×a length=1.5 cm×1.5 cm), and drying it for 1 hourat the room temperature and then subjecting it to a thermal annealingfor 1 hour at about 160° C. Then, a SEM (scanning electron microscope)image of the formed polymer layer was obtained. FIGS. 1 to 5 are resultsof Examples 1 to 5, respectively. As confirmed from Figures, in a caseof the block copolymers of Examples, self assembled polymer layer havingline patterns are effectively formed. However, an appropriate phaseseparation was not realized in Comparative Example. For example, FIG. 6is the SEM result of Comparative Example 3, and it is confirmed thateffective phase separation was not realized.

Test Example 3

Further, block copolymers having different volume fractions wereprepared according to the same method as in Example 1, except that themolar ratios of the monomers and the macroinitiators were controlled.

The volume fractions are as below.

TABLE 3 Volume fraction of Volume fraction of the first block the secondblock Sample 1 0.7 0.3 Sample 2 0.59 0.41 Sample 3 0.48 0.52

The volume fraction of each block of the block copolymer was calculatedbased on a molecular weight measured by a GPC (Gel PermeationChromatograph) and the density at the room temperature. In the above,the density was measured by the buoyancy method, specifically, wascalculated by a mass in solvent (ethanol), of which a mass and a densityin the air are known, and the GPC was performed according to the abovedescribed method.

The polymer layer was obtained by spin coating a coating solutionprepared by dissolving the block copolymer of each sample influorobenzene to a solid content of about 0.7 weight % on a siliconewafer so as for a coated thickness to be 5 nm (a coated area: awidth=1.5 cm, a length=1.5 cm), and drying it for 1 hour at the roomtemperature and then subjecting it to a thermal annealing for 1 hour atabout 160° C. Then, the GISAXS was performed and the results areillustrated in Figures. FIGS. 7 to 9 are the results of the samples 1 to3, respectively. From the figures, it can be confirmed that the in-planephase diffraction pattern is observed with respect to the samples 1 to3.

Test Example 3 GISAXS Diffraction Pattern Confirmation

FIG. 10 shows the result of the GISAXS (Grazing Incident Small Angle Xray Scattering) analysis of the block copolymer of Example 1 performedwith respect to the hydrophilic surface of which a contact angle at theroom temperature with respect to the purified water was about 5 degrees,and FIG. 11 shows the result of the GISAXS (Grazing Incident Small AngleX ray Scattering) analysis of the block copolymer of Example 1 performedwith respect to the hydrophobic surface of which a contact angle at theroom temperature with respect to the purified water was about 60degrees. From FIGS. 10 and 11, it can be confirmed that the in-planephase diffraction patterns are observed in any case. From the above, itcan be confirmed that the block copolymer can show the vertical aligningproperties with respect to various substrates.

Further, by using the block copolymer of Example 1, polymer layers wereformed by the same method as described above. The polymer layers wereformed on a silicone substrate that was treated with the piranhasolution that had a contact angle of 5 degrees of the purified water atthe room temperature, a silicone oxide substrate that had a contactangle of 45 degrees of the purified water at the room temperature and aHMDS (hexamethyldisilazane) treated silicone substrate that had acontact angle of 60 degrees of the purified water at the roomtemperature, respectively. FIGS. 13 to 15 are the SEM images regardingthe polymer layers on the surface having the contact angles of 5degrees, 45 degrees and 60 degrees, respectively. From the Figures, itcan be confirmed that the block copolymer forms the phase separationstructure irrespective of surface properties of substrates.

Test Example 4 XRD Analysis

The result of the XRD analysis performed regarding the block copolymeraccording to the above method is stated in Table 3 below (In a case ofthe Comparative Example 3, no peak was observed in a range of thescattering vectors from 0.5 nm⁻¹ to 10 nm⁻¹).

TABLE 3 Exs. Com. Exs. 1 2 3 4 5 1 2 3 Chain-forming 12 8 10 14 16 4 112 atoms n/D 3.75 3.08 3.45 4.24 4.44 2.82 1.98 — the q value 1.96 2.412.15 1.83 1.72 4.42 3.18 — (unit: nm⁻¹) FWHM 0.57 0.72 0.63 0.45 0.530.97 1.06 — (unit: nm⁻¹) The q value: the scattering vector Thechain-forming atoms: the number of the chain-forming atoms in the firstblock n/D: the value calculated by the formula (nq/(2 × π)) (n: thenumber of the chain-forming atoms, q is the scattering vector which iswithin a range from 0.5 nm−1 to 10 nm−1 at which and at which a peakhaving the largest area is observed within the above range of thescattering vectors)

Test Example 5 Properties Measurement of Block Copolymers

The results of evaluations regarding each block copolymer measured asabove method are stated in the below Table.

TABLE 4 Exs. Com. Exs. 1 2 3 4 5 1 2 3 First De 1 1.04 1.02 0.99 1.001.11 1.19 0.93 Block VF 0.66 0.57 0.60 0.61 0.61 0.73 0.69 0.76 SecondDe 1.57 1.57 1.57 1.57 1.57 1.57 1.57 1.57 Block VF 0.34 0.43 0.40 0.390.39 0.27 0.31 0.24 Difference of 0.57 0.53 0.55 0.58 0.57 0.46 0.380.64 De De: density (unit: g/cm³) VF: volume fraction Difference of De:the absolute value of the difference between the densities of the firstand the second block

What is claimed is:
 1. A block copolymer, comprising a first block and asecond block different from the first block, wherein an absolute valueof a difference between surface energies of the first block and thesecond block is from 2.5 mN/m to 7 mN/m.
 2. The block copolymeraccording to claim 1, wherein the first block has a higher surfaceenergy than the second block.
 3. The block copolymer according to claim1, wherein the surface energy of the first block is from 20 mN/m to 35mN/m.
 4. The block copolymer according to claim 1, wherein an absolutevalue of a difference between densities of the first block and thesecond block is 0.3 g/cm³ or more.
 5. The block copolymer according toclaim 1, wherein the first block or the second block comprises anaromatic structure.
 6. The block copolymer according to claim 5, whereina linear chain having 8 or more chain-forming atoms is linked to thearomatic structure.
 7. The block copolymer according to claim 6, whereinthe linear chain is linked to the aromatic structure via an oxygen atomor a nitrogen atom.
 8. The block copolymer according to claim 5, whereinthe aromatic structure comprises at least one halogen atom.
 9. The blockcopolymer according to claim 8, wherein the halogen atom is a fluorineatom.
 10. The block copolymer according to claim 1, wherein the firstblock comprises an aromatic structure that does not comprise a halogenatom and wherein the second block comprises an aromatic structurecomprising the halogen atom.
 11. The block copolymer according to claim1, wherein a linear chain having 8 or more chain-forming atoms is linkedto the aromatic structure of the first block.
 12. The block copolymeraccording to claim 9, wherein the linear chain is linked to the aromaticstructure via an oxygen atom or a nitrogen atom.
 13. The block copolymeraccording to claim 1, wherein the first block is represented by Formula1 below:

wherein the R is hydrogen or an alkyl group having 1 to 4 carbonatom(s), the X is a single bond, an oxygen atom, a sulfur atom,—S(═O)₂—, a carbonyl group, an alkylene group, an alkenylene group, analkynylene group, —C(═O)—X₁— or —X₁—C(═O)—, where the X₁ is an oxygenatom, a sulfur atom, —S(═O)₂—, an alkylene group, an alkenylene group oran alkynylene group and the Y is a monovalent substituent comprising acyclic structure to which a chain having 8 or more chain-forming atomsis linked.
 14. The block copolymer according to claim 1, wherein thesecond block is represented by Formula 3 below:

wherein the X₂ is a single bond, an oxygen atom, a sulfur atom,—S(═O)₂—, an alkylene group, an alkenylene group, an alkynylene group,—C(═O)—X₁— or —X₁—C(═O)—, where the X₁ is a single bond, an oxygen atom,a sulfur atom, —S(═O)₂—, an alkylene group, an alkenylene group or analkynylene group, and the W is an aryl group comprising at least onehalogen atom.
 15. The block copolymer according to claim 1, of which anumber average molecular weight is from 3,000 to 300,000.
 16. The blockcopolymer according to claim 1, of which a polydispersity (Mw/Mn) isfrom 1.01 to 1.60.
 17. A polymer layer comprising a self assembledproduct of the block copolymer of claim
 1. 18. The polymer layeraccording to claim 17, exhibiting an in-plane phase diffraction patternin a grazing incidence small angle X ray scattering.
 19. A method forforming a polymer layer, comprising forming the polymer layer comprisinga self assembled product of the block copolymer of claim
 1. 20. Apattern-forming method comprising selectively removing the first blockor the second block of the block copolymer from a laminate comprising asubstrate and a polymer layer that is formed on the substrate and thatcomprises a self-assembled product of the block copolymer of claim 1.